Downtube for a bicycle



FIG. 1 is a front perspective view of a downtube for a bicycle showingmy new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken line showing of the various unshaded regions of the downtubefor a bicycle illustrates environmental structure and forms no part ofthe claimed design.

CLAIM The ornamental design for a downtube for a bicycle, as shown anddescribed.